Abstract: A free-space optical communication apparatus includes a storage unit which stores angle-setting information for the mirror for communicating with each of the plurality of other apparatuses, a mirror driving unit which drives the mirror to an angle corresponding to the stored angle-setting information, an optical detecting unit which, on one occasion for communicating with a specified communication apparatus among the plurality of other apparatuses, detects the incident state of an optical beam sent from the specified apparatus, and a control unit which, based on the detected incident state of the optical beam, determines angle-correcting information for correcting the stored angle-setting information for the specified apparatus, and which, on the next occasion for communicating with the specified apparatus, uses the mirror driving unit to drive the mirror to an angle corresponding to the angle-setting information corrected by the angle-correcting information.

Abstract: An optoelectronic transceiver including an optoelectronic transmitting unit disposed along an optical axis and having a radiation-emitting layer region and an active radiation-sensitive layer region. The optoelectronic transceiver further including an optoelectronic receiving unit disposed along the optical axis and is disposed in bridge-like fashion above the optoelectronic transmitting unit. The optoelectronic receiving unit having an active radiation-sensitive layer region disposed perpendicular to the optical axis and located in a thin membrane, which is disposed immediately in front of the radiation-emitting layer region of the optoelectronic transmitting unit, and a radiation-emitting layer region.

Abstract: An optical transponder/transceiver for intermediate range (e.g., 10-50 km) optical communication applications utilizes an electroabsorption modulated laser for the transmitting device. Preferably, the laser operations at a wavelength of approximately 1310 nm and comprises an electroabsorption modulated Fabry-Perot laser.

Abstract: An optical transceiver providing a carrier; a cover couplable to a portion of the carrier to define a transceiver enclosure; and, an electro-optical assembly supported in the enclosure is provided. A coupling mechanism and cooperating structure are particularly adapted to define pivoting motion of the cover relative to the carrier, whereby interference of the cover and the electro-optical assembly is avoided. Methods of assembling the transceiver components are present.

Abstract: Signal reflection mitigation in fiber-optic networks. Signal reflections are mitigated using near-end echo cancellation, threshold adjustment and/or error correction code. Signal reflections in a receive signal that are caused by near-end connectors may be mitigated using an echo cancellation signal. Signal reflections caused by other discontinuities on a fiber-optic network may be mitigated by using error correction code. Also, an average value of a reflected signal maybe detected and used to set an adjusted threshold value to interpret logical values of an electronic or optical signal.

Abstract: Internal communication signals in a stored program controlled system comprising a plurality of units configured to process signals are provided by a free space optical beam line which is proximal to all of the plurality of units. The free space beam line is configured to contain optically encoded signals which comprises signals transmitted between and/or among the plurality of units. Each unit includes a probe for injecting optically encoded signals in the free space beam line and/or and for receiving optically encoded signals from the free space beam line. Advantageously, there may be a first terminal at a first end of the beam line to configure to transmit and terminate the optically encoded signals and a second terminal unit at the second end of the free space beam line configured to transmit and terminate the optically encoded signals.

Abstract: A controller for controlling a transceiver having a laser transmitter and a photodiode receiver. The controller includes memory for storing information related to the transceiver, and analog to digital conversion circuitry for receiving a plurality of analog signals from the laser transmitter and photodiode receiver, converting the received analog signals into digital values, and storing the digital values in predefined locations within the memory. Comparison logic compares one or more of these digital values with limit values, generates flag values based on the comparisons, and stores the flag values in predefined locations within the memory. Control circuitry in the controller controls the operation of the laser transmitter in accordance with one or more values stored in the memory. A serial interface is provided to enable a host device to read from and write to locations within the memory.

Abstract: A high-speed optical data link includes a system circuit board, a first ASIC coupled to convey electrical information to and from up level data management circuits, and a second ASIC electrically coupled to the first ASIC. A fiber optic module mounted on the system circuit board including a receiver, a transmitter and the second ASIC. The receiver includes a photo-diode positioned to receive optical signals, a trans-impedance amplifier electrically coupled to the photo diode, and a post-amplifier electrically coupled to the trans-impedance amplifier and to the second ASIC. The transmitter includes a laser positioned to convey optical signals to a remote optical receiver and a laser driver electrically coupled to the laser and to the second ASIC.

Abstract: This invention extends the range of optical data of mobile device by trading speed for distance as well as integrating a plurality of pulses over time to define a single bit of information. The present invention uses a number of integrated pulses to represent a single bit instead of utilizing a one to one correspondence between pulses and bits. The present invention executes a range extender application which executes on the mobile device without any hardware modification to the mobile device. The range extender application causes the optical transmitter to “stutter” or repetitively emanate the identical pulse representing a bit of information. Sufficient photons are thereby gathered at a receiver to reach a predetermined threshold. A tradeoff of the data transmission frequency in this invention is that a signal intensity drops by a factor of 100 when distance increases by a factor of 10 yielding a distance/intensity ratio of {fraction (1/10)}.

Abstract: An optical transmission system for compensating for transmission loss includes a transmitting apparatus for serializing a plurality of n (n is a natural number)-bit channel data received from the outside in response to a predetermined clock signal, converting the serialized channel data and the predetermined clock signal into a current signal whose magnitude changes corresponding to an error detection signal, and outputting optical signals having optical output power corresponding to the magnitude of the current signal, a first optical fiber for transmitting the optical signals, a receiving apparatus for recovering the n-bit channel data and the predetermined clock signal from the optical signals received through the first optical fiber, detecting transmission loss generated when the optical signals are transmitted and received, optically converting the transmission loss, and outputting the optically converted transmission loss as the error detection signal, and a second optical fiber for transmitting the opt

Abstract: An Improved Signal Receiver Having Wide Band Amplification Capability is disclosed. Also disclosed is a receiver that is able to receive and reliably amplify infrared and/or other wireless signals having frequency bandwidths in excess of 40 MHz. The receiver of the present invention reduces the signal-to-noise ratio of the received signal to ?th of the prior systems. The preferred receiver eliminates both the shunting resistor and the feedback resistor on the input end by amplifying the signal in current form. Furthermore, the receiver includes transconductance amplification means for amplifying the current signal without the need for Cascode stages. Finally, the receiver includes staged amplification to amplify the current signal in stages prior to converting the signal into a voltage output.

Abstract: An interference-reducing optoelectronic device determines the value of a current data bit in an optical data stream. A receiver receives the optical data stream, which is converted to a series of samples by a D/A converter. A set of adaptive filters, each filter corresponding to a unique possible value for one or more prior data bits, filters the series of samples utilizing variable tap coefficients to generate filtered output values. The variable tap coefficients are at least partially different than the variable tap coefficients of another adaptive filter. Comparators compare the filtered output values against filter-specific adaptive threshold values to generate tentative values for the current data bit. A delay mechanism delays a determined value for the prior data bits, and a selection mechanism determines the value of the current data bit by selecting the tentative value corresponding to the delayed determined value of the prior data bits.

Abstract: A Fiber-wireless uplink consists of a wireless channel followed by a radio-over-fiber (ROF) link. Typically, nonlinear distortion of the ROF link is the major concern when the radio frequency is only a few GHz. This especially severe in the uplink, because of the multipath fading of the wireless channel. A Hammerstein type decision feedback equalizer is described for the fiber wireless uplink, that compensates for nonlinear distortion of the ROF link as well as linear dispersion of the wireless channel. Since the linear and nonlinear parts of the receiver are separated, tracking the fast changing wireless channel is virtually independent of compensating for the relatively static nonlinearity. Analytical results show that the receiver provides excellent compensation with notably less complexity.

Abstract: A fiber optic transceiver capable of bi-directional communication comprises an incoming optical (downlink) signal, a detector comprising a detecting surface configured to detect a detected portion of the incoming optical signal that strikes the detecting surface, and a light modulator for modulating a reflected (uplink) signal. The reflected signal comprises a reflected portion of the incoming signal. The light modulator comprises a controllable reflection member for modulating the reflected signal, and a controller configured to control the controllable reflection member. The controllable reflection member implements micro-electro-mechanical systems (MEMS) technology wherein micro-reflective surfaces are physically positioned or oriented by the control signal, thereby affecting reflection and diffraction in such a way as to modulate the intensity of light entering an uplink channel.

Abstract: The present invention provides an apparatus and a method for improved connectivity in wireless optical networks. Therefore at least two or more receiving units are used which receive an infrared signal and convert it to a digital signal. The digital signals represent data in the form of frames whereby each frame comprises at least a data field and a header field containing a preamble. A selector determines a measure related to the signal-to-noise ratio of the preamble and compares the measures in order to select the best suited signal for further processing.

Abstract: The band management circuit of the present invention is utilized in a fiber-optic network that uses, for example, ATM-PDS, in order for an SLT to control the transmissions of a plurality of ONU, which are accommodated by this SLT. The band management circuit of the present invention stores one time in a table an identification number, which specifies a multi-point device for which transmission is authorized. An identification number stored in a table is generated by a table generating portion. The table generating portion sequentially generates the identification number of a number of transmission authorizations determined in accordance with a transmission band provided to respective multi-point devices. A write/read control portion sequentially writes to a table identification number data generated by the table generating portion.

Abstract: An optical fiber transmission line for realizing satisfactory long haul transmission characteristics using two kinds of optical fibers. The optical fiber transmission line includes a plurality of local dispersion compensating spans, wide dispersion compensating spans disposed at predetermined intervals, and optical repeating amplifiers to connect each span. The local dispersion compensating span includes a first optical fiber with positive dispersion having an effective core area of 130 &mgr;m2 or more and a second optical fiber with a negative dispersion value of −50 ps/nm/km or less to transmit the light output from the first optical fiber. The wide dispersion compensating span consists of a third optical fiber having the same configuration and composition with the first optical fiber.

Abstract: A single-chip integrated circuit, sometimes called a controller, controls operation of a transceiver having a laser transmitter and a photodiode receiver. The controller includes memory for storing information related to the transceiver, and analog to digital conversion circuitry for receiving a plurality of analog signals from the laser transmitter and photodiode receiver, converting the received analog signals into digital values, and storing the digital values in predefined locations within the memory. Comparison logic compares one or more of these digital values with predetermined setpoints, generates flag values based on the comparisons, and stores the flag values in predefined locations within the memory. Control circuitry in the controller shuts off the laser transmitter in response to comparisons of signals with predetermined setpoints that indicate potential eye safety hazards.

Abstract: A single-chip integrated circuit, sometimes called a controller, controls operation of a transceiver having a laser transmitter and a photodiode receiver. The controller includes memory for storing information related to the transceiver, and analog to digital conversion circuitry for receiving a plurality of analog signals from the laser transmitter and photodiode receiver, converting the received analog signals into digital values, and storing the digital values in predefined locations within the memory. Comparison logic compares one or more of these digital values with predetermined setpoints, generates flag values based on the comparisons, and stores the flag values in predefined locations within the memory. Control circuitry in the controller shuts off the laser transmitter in response to comparisons of signals with predetermined setpoints that indicate potential eye safety hazards.

Abstract: A method of and apparatus for optimizing a minimum turn around time (MTAT) between (a) a reception by a first device of a first infrared data communication (IRDC) frame sent from a second device and (b) a transmission by the first device of a second IRDC frame to the second device. The MTAT value received from the second device is loaded into a storage device. The first IRDC frame from the second device is received, and a counter of the first device either resets upon reception of each of the plurality of characters of the first IRDC frame or increments when none of the plurality of characters are received. The first device transmits the second IRDC frame to the second device when the counter value reaches the MTAT value.

Abstract: In a spatial transmission optical transceiver, signals of two lines from a feeder-affixed twisted pair line 17 which is a data transmission line based on IEEE1394 standard are converted to signals of one line by a code conversion circuit 14, and further converted to optical signals and emitted to space by a optical transmitter 15. The optical signal transmitted through the space is converted to an electrical signal by a optical receiver 16. The code conversion circuit 14 receiving the electrical signal of one line thus converted to signals of two lines, and transmits the signals onto the feeder-affixed twisted pair line 17. The electrical signal from the optical receiver 16 is input to an interception and insertion/removal detection circuit 13 to detect the presence or absence of the optical signal and judge whether the received signal is a reflection signal, thereby detecting the interception of a communication path and the insertion/removal of a signal line connected to a confronting optical transceiver.

Abstract: The present invention offers a polarization mode dispersion compensator and a compensation method for polarization mode dispersion having simple constitution and being strong against external disturbances. The polarization mode dispersion compensator, a representative example of the present invention, is provided with a compensation circuit for polarization mode dispersion, a degree of polarization measuring circuit, and a control circuit. An optical signal is input to the compensation circuit for polarization mode dispersion through an optical fiber, and after the process of compensation for polarization mode dispersion, it is output to an optical fiber. An optical coupler divides a part of the optical signal passing through the optical fiber. The degree of polarization measuring circuit finds the degree of polarization of the divided optical signal.

Abstract: A high-speed optical data link includes a system circuit board, a first ASIC coupled to convey electrical information to and from up level data management circuits, and a second ASIC electrically coupled to the first ASIC. A fiber optic module mounted on the system circuit board including a receiver, a transmitter and the second ASIC. The receiver includes a photo-diode positioned to receive optical signals, a trans-impedance amplifier electrically coupled to the photo diode, and a post-amplifier electrically coupled to the trans-impedance amplifier and to the second ASIC. The transmitter includes a laser positioned to convey optical signals to a remote optical receiver and a laser driver electrically coupled to the laser and to the second ASIC.

Abstract: A modularized network component system that includes a transceiver module and a separate accessory module, and enables the transmissions range of the transceiver module to be augmented by the accessory module, is disclosed. According to one aspect of the present invention, an optical network includes a fiber, a first device, and a second device. The first and second devices are coupled to the fiber such that the second device is in communication with the first device through the fiber. The second device includes a first modular subsystem that is arranged both to transmit data and to receive data through the fiber. The first modular subsystem is substantially physically decoupleable from the second device and from the fiber such that the first modular subsystem may be readily replaced within the second device by another modular subsystem.

Abstract: A polarization scrambler and a polarization mode dispersion (PMD) compensation system compensate for PMD on an active optic fiber. The polarization scrambler scrambles a state of polarization of an optical signal that carries user information. The PMD compensation system then receives the optical signal over the active optic fiber. The PMD compensation system measuring a differential group delay and principal states of polarization of the PMD in the active optic fiber. The PMD compensation system then determines a modification of the optical signal based on the differential group delay and the principal states of polarization of the PMD. The PMD compensation system modifies the optical signal in the active optic fiber to compensate for PMD based on the determination of the modification. The PMD compensation system then transmits the optical signal.